1. Field of the Invention
This invention relates in general to methods and apparatus for reproducing image patterns.
2. Description of the Prior Art
A method for dot and line-wise reproduction of image patterns has been described in U.S. Pat. No. 3,904,816 where under digital intermediate storage of image signal sequences obtained line-wise, at least two associated image signal sequences are stored and withdrawn from storage synchronously and where the reproduction is influenced by either the functions of certain characteristic values of an image signal sequence or from both image sequence signals.
This method is applied in the reproduction technique if images are copied into each other and the image data have previously been digitally stored. Such method has the advantage of offering great flexibility in conjunction with high safety in the production of printing cuts by obtaining variations and combinations of image patterns.
In a typical application for example, two image originals may be present with image I being a background and image II being an object which is to be combined with the background. Usually the images are not available in the necessary size or in the required cut-out so that second originals have been produced in a separate operation which have the necessary final scale and cut-out for the particular desired combination. A mask is produced manually from the image to be copied into the background. The second originals and the masks are scanned stored digitally and used according to the method described in U.S. Pat. No. 3,904,816.
However, it happens that the position of the image II to be copied within image I does not precisely match. In that case, a new corrected mask would have to be produced and the operation of overprinting would have to be repeated which is time consuming and costly.
An additional disadvantage of this method of the prior art resides in the fact that a second original must be produced from each original in the corresponding scale and with the corresponding cut-out and the original then must be scanned and the data thus obtained must be stored. Hence, an additional optical reduction printing operation is necessary causing increased expenditure in time and money and a reduction in the quality of the image data.